Spiral-wound cardboard forms are very well known, being used as the central core for paper toilet roll, and also as containers for candies and foodstuffs; as forms for pouring concrete pillars, and as bulk shipping containers. Such prior art containers are generally characterized by the porous nature of the spiral-wound wall.
In the field of multi-paned glazing lights, such as windows, patio doors, rooflights and the like, in which two or more panes of glass or other glazing material are framed in spaced-apart, edge-sealed relation, various efforts have been made to provide a spacer/seal possessing high sealing integrity combined with low thermal conductivity. The most widely used spacer/seals have been of aluminum extruded sections, more recently incorporating some form of thermal break at the "inner" surface, i.e. the surface bounding the interior space enclosed by the glass panes. Such lights are subject to "sweating" and frost formation under extremely cold conditions due to thermal bridging between the adjacent panes, caused by heat conduction by the spacer.
In the case of hospital and other institutional facilities, widely spaced panes have in many instances utilized stainless steel spacers of considerable lateral width, where sound transmission has proved to be a problem.
Previous efforts by the present inventor in the provision of improved non-metallic spacer/seals have been directed to utilizing paper, cardboard and other suitable low-cost fibrous sheet materials laminated into ribbon form, and incorporating one or more sealing coatings to provide a cohesive, hermetic sealing layer selected from a family of superior plastic substances. These substances also may in many instances form a part of the ribbon laminating process. The thus-formed ribbons are generally scored longitudinally, to provide fold lines by means of which the ribbons can be formed into an elongated hollow spacer/seal formulation, for bonding between a pair of panes, to form a sealed light.
This prior process is quite practical, to yield a low-cost, effective spacer/seal. As with any product, however, the costs both of material and of production require to be held to the minimum. Also, in the case of mass production, the provision of a suitable seal that is completely ready for installation, without requiring assembly from a pre-formed ribbon into its tubular form, would comprise a distinct advantage.